Conventionally, systems have been known which share vehicle information among vehicles through intervehicle communication and which carry out vehicle control such as auto cruise control and driving support.
For example, Patent Document 1 discloses a mobile wireless communication apparatus and its intervehicle communication method that intend to achieve safe driving through intervehicle communication and to make efficient use of wireless resources by reducing the total communication traffic flowing through a wireless communication network.
In addition, Patent Document 2 discloses a method of grouping vehicles that carry out intervehicle communication, and of reducing the use load of a communication band and relieving congestion by optimizing the data transfer volume between the groups.
Furthermore, Patent Document 3 discloses a collision avoidance system in which a relay apparatus collects vehicle information transferred between vehicles, brings the vehicle information items from the individual vehicles together into single data, and transmits to the individual vehicles all together. Thus, it reduces the use load of the communication band, and decides the danger of a collision between vehicles from the mutual vehicle information acquired between the vehicles.